We shall formulate an analysis of the ordinary notion of intentional action that clarifies a commonsense distinction between intentional and nonintentional action. Our analysis will build on some typically neglected considerations about relations between lucky action and intentional action. It will highlight the often- overlooked role of evidential considerations in intentional action, thus identifying the key role of certain epistemological considerations in action theory. We shall also explain why some vagueness is indispensable in a characterization of intentional action as ordinarily understood.